Hong Kong leader Carrie Lam warned yesterday that her government is prepared to intervene in the affairs of the city's metro network operator.

It came as both her administration and MTR Corporation came under further pressure over a train crash that led to a two-day service disruption on the Tsuen Wan Line between Central and Admiralty stations.

The leader told lawmakers in a Legislative Council session that when government agencies or listed companies such as the MTR face a greater workload and calls for more transparency, cracks will show.

"So the governing boards of these public bodies need to have the ability to reflect upon and review themselves," she said. "If it requires the government's intervention to instil change, I am more than willing to do so."

The government, a major shareholder in MTR, is ready to step in to ensure that the rail operator strikes the right balance between public and business interests, she added.

Secretary for Transport and Housing Frank Chan told the media that the government will observe the current mechanism when deciding on the penalty, adding: "We need to look into the seriousness of the incident and appropriateness of penalty in due course."

Mrs Lam's warning came after MTR's management apologised to passengers yesterday morning. Neither has said whether commuters will be compensated.

Two subway trains collided early on Monday during a test of a new signalling system. A train driver was injured during the trial, which was closed to the public.

A software glitch has been blamed for the signalling fault that led to the collision - the first such accident in 40 years of MTR operations.

Yesterday morning, outgoing MTR chairman Frederick Ma said during an inspection of the platform that a committee - which includes Thales, the French supplier of the system - has been set up to investigate the accident.

He vowed that the team will "conduct a thorough investigation" and "put safety above all else" before launching the new system.

Thales, in a joint venture with another French company Alstom, was awarded a €330 million (S$506 million) contract in 2015 to upgrade MTR's signalling system.

The new system was to be rolled out in the latter half of this year. But the upgrade is now expected to be delayed.

It is expected to take the committee two to three months to study the data arising from the train collision, but Thales will hand in a preliminary report this week.

Services between the two affected stations resumed after the damaged trains were removed from the accident site underground and repair work around Central station was completed.

Public confidence in Hong Kong's usually reliable rail operator has been shaken by the accident.

The safety of the Thales system has come under scrutiny, as it was also linked to a train collision in Singapore in 2017 - even though both Thales and the Singapore authorities have said that the two accidents were different.